The invention relates generally to agricultural machines and, more particularly, to a hydraulic adjusting device, especially one for selectively actuating the blades used for cutting up the harvested crop in agricultural harvesting machines.
Various implementations of adjusting devices of this type that are used for differing purposes are already known. Thus, for example, a cutter device for harvested crops is described in DE 28 18 850 C2. This device is disposed in a feed channel of a tractor-drawn self-loading forage wagon. It comprises cutter blades which co-operate with the crop-advancing mechanism and which are active in the feed channel when in their working position. The cutter blades are held in their working position by means of a support device, and are moveable therefrom into a position where they are no longer effective. In this arrangement, the support device is formed by a controllable hydraulic adjusting device. One hydraulic adjusting device is associated with each cutter blade and the adjusting devices are coupled to the hydraulic plant in the tractor through the intermediary of a hydraulic accumulator. This implementation permits the cutter blades to retract automatically from the cutting zone should an overload occur due to the effects of a foreign body or some other form of obstruction. The blades automatically swing back into their working position once the cause of the disturbance has been removed. With this arrangement however, it is not possible to selectively alter the number of effective cutter blades so as to adjust the degree to which the crop is cut up in dependence on the particular crop being harvested and the usage to which it will be put.
In the cutter device comprising a plurality of pivotal cutter blades illustrated in DE 43 02 199 C2, the blades are moved into the cutting position by means of hydraulically controllable support means. The arrangement of blades as a whole, or a selectable number thereof, can be released from the support means so as to pivot into a non-cutting position by means of a control device. Here it is possible to make adjustments to allow for the actual harvesting conditions but the manufacturing costs are very high due to the complicated construction.
It is an object of the present invention to overcome one or more of the deficiencies described above.
Another object is to construct a hydraulic adjusting device or selectively actuating functional elements such as shear blades for example, in such a manner that a functionally effective solution having a simple and compact construction is obtained at low manufacturing cost.
In accordance with the invention there is provided a hydraulically-actuated blade actuating device for use on agricultural machines and including a plurality of blades each having a rear region, means for mounting said blades for pivotal movement as an entity and in differing numbers between a cutting position and a non-cutting position; a plurality of contact rollers each for engaging the rear region of at least one blade; means defining a block having a plurality of adjacent hydraulic cylinders disposed therein, the block having a plurality of borings operatively connected to the hydraulic cylinders for supplying hydraulic fluid thereto, each hydraulic cylinder being associated with each blade and having a piston rod engaged with a respective contact roller; and means for delivering hydraulic fluid to selected hydraulic cylinders to extend the respective piston rods thereby engaging the respective contact rollers with the rear region of the respective blades and moving said blades to the cutting position.
An implementation permits the spatial requirements of the device to be kept low by virtue of the compact construction. Various ways of activating the individual functional elements in the number required can be achieved through appropriate actuation of the existing hydraulic valves. The resultant wear and tear and the maintenance costs are very low due to the fact that only a few moveable components are involved. The simple implementation of the blocks in the form of a flange-like construction allows the whole adjusting device including the appertaining hydraulic valves to be pre-assembled.
In an embodiment of the invention, the following are provided: blades with a rear region which can pivot as an entity and in differing numbers into a cutting or a non-cutting position, a contact roller, adjacent hydraulic cylinders which are disposed in a block and connected via a through bore, each hydraulic cylinder being associated with each blade and having a piston rod that makes contact with the rear region of the associated blade via the contact roller; and borings which are arranged in the block such that each one of these borings is connected to the space within a hydraulic cylinder via a respective connecting bore.
These, and other objects and advantages of the present invention, will become apparent as the same becomes better understood from the following detailed description when taken in conjunction with the accompanying drawings.